Mental illness and normal aging among the very old have been neglected in both cross-sectional and longitudinal research. Yet the very old are an important group to study, both because they are an elite who have survived most of their birth cohort, and because aging processes and problems accelerate among them. This project will examine (1) the antecedents of organic and functional mental illness in comparisons to the antecedents of normal aging among the old-old; (2) the consequences of mental illness and normal aging for physical, mental, and social processes of aging for treatment and care; for social and economic problems; and the predictors of various consequences; and (3) the differences between the normal and the mentally ill very old in family and social support, and how they change over time. A representative sample of 300 very old (men 73 and older and women 78 and older) community residents will be given comprehensive physical, psychiatric, and social examinations. They will be classified as normal, as primarily organic mentally imparied, or as primarily functionally impaired. Each person will have two annual follow-up examinations. In addition, antecedent information will be available on each person from the 1972 survey in which they participated. This project will provide valuable information for mental illness prevention, improved care of the mentally ill, and programs to increase successful aging among the very old.